Human gut microbiota and Parkinson Disease

Abstract

Human gut microbiota (GM) has now been  accepted as a potential modulator ofhuman biology.  Although new to the world of science, GM's impaction  brain and behavior has drawn great attention around the  globe. Studies have now proven that GM can directly  or indirectly modify brain neurochemistry via various  mechanisms like neural, immune and endocrine. The  intestinal microbiota influence neurodevelopment,  modulate behavior, and contribute to neurological  disorders. This presentation is an overview of recent  findings regarding the GM -brain axis in PD (Braniste et  al. 2014; Sampson et al. 2016)  Parkinson disease (PD) is the second-most  common neurodegenerative disorder. PD patients show  alpha-synuclein deposits and neurodegeneration in the  enteric nervous system as well as breakdown of the  mucosal barrier, bacterial invasion, and mucosal  inflammation in the colon. Alterations in GM and  increased gut permeability may influence PD  pathophysiology via epigenetic processes that alter  αSyn regulation (Matsumoto et al. 2010).  Sampson et al. (2016) suggest that GM are  required for the hallmark motor and GI dysfunction in a  mouse model of PD, via postnatal gut-brain signaling by  microbial molecules that impact neuroinflammation and  αSyn aggregation. They propose that GM regulate  movement disorders and suggest that alterations in the human microbiome represent a risk factor for PD. GM  do not only affect gut physiology, but there is also an  intense bidirectional interaction with the brain  influencing neuronal activity, behavior, as well as levels  of neurotransmitter receptors, neurotrophic factors, and  inflammation. Recently, gut microbiome alterations in  PD subjects and a connection between GM and motoras  well as non-motor symptoms have been described  (Sampson et al. 2016; Parashar and Udayabanu 2017)